Table 1. Socio-demographic characteristics of the study population (N = 555).
| Socio-demographic characteristics | Total population N = 555 | Never used nitrous oxide n = 466 | Used nitrous oxide ≥ 1 time n = 86 | p-value |
|---|---|---|---|---|
| Age in years, mean (SD) | ||||
| Age in years | 15.6 (0.83), range 14–18 | 15.6 (0.82) | 15.6 (0.91) | 0.701 |
| Gender, n (%) | ||||
| Male | 294 (53.0) | 248 (53.2) | 44 (51.2) | 0.726 |
| Female | 261 (47.0) | 218 (46.8) | 42 (48.8) | |
| Ethnic background, n (%) | ||||
| Dutch | 399 (71.9) | 343 (73.6) | 53 (61.6) | 0.027 |
| Non-Dutch | 156 (28.1) | 123 (26.4) | 33 (38.4) | |
| School level, n (%) | ||||
| Pre-vocational education | 288 (51.9) | 226 (48.5) | 61 (70.9) | <0.001 |
| Senior secondary & pre-university education | 267 (48.1) | 240 (51.5) | 25 (29.1) | |
| Living situation, n (%) | ||||
| With both my parents | 379 (68.3) | 327 (70.2) | 49 (57.0) | 0.023 |
| Not with both my parents | 176 (31.7) | 139 (29.8) | 37 (43.0) |
Note: bold numbers indicate a statistically significant (p<0.05) difference between the group that never used nitrous oxide versus the group that did use nitrous oxide, calculated using an independent-samples t-test (continuous variables) or a chi-square test (categorical variables). There were zero missing answers on the socio-demographic questions. There were three missing answers on the question regarding the use of nitrous oxide.